Wood-screw



(NoModex.)

H. K. JONES- WooDsGRBW.

No. 470,804. Patented Mau'.y 15.1892.

" ATENT Fries.

HORACE K. JONES, OF HARTFORD, ASSIGNOR TO THE RUSSELL d ERVINMANUFACTURING COMPANY, OF NEI/V BRITAIN, CONNECTICUT.

Woon-SCREW.

SPECIFICATION forming part of Letters Patent No. 470,804, dated March15, 1892. Application led November 11, 1891. Serial No. 411,608. (Nomodel.)

To @ZZ whoml it may concern,.-

Be it known that I, HORACE K. JONES, a citizen of the United States,residing at Hartford, in the county of Hartford and State of- 5Connecticut, have invented certain new andf useful Improvements inWood-Screws, of which the following is a specification.

My invention relates to yimprovements in wood-screws; and the objects ofmy improvement are to produce a wood-screw with a large or full shankthat will ream its own way into the Wood, to produce a giinlet-pointed`wood-screw with a ribbed or fluted shank that will fill a holesubstantially the saine as with a solid shank, to produce a screw with arolled thread that is straight throughout its length, to facilitate themanufacture of the screw, especially in rolling the gimlet-point, and ingeneral to increase the efficiency and utility of the article. x

In the accompanying drawings, Figures 1, 2, and 3 are each sideelevations of my screw, differing from each other in minor details. Fig.4 is a transverse section of my screw on the line :r x of Fig. l; andFig. 5 is a sectional View of a piece of wood, illustrating the actionof my screw.

a designates the gimlet-point; b, the threaded body, both of ordinaryform; c, the shank, and d the ordinary beveled head and for which theordinary half-round head may be substituted, if desired.

The screw-head is provided with a nick or slot to adapt it forengagement by a driver for turning the screw axially to force it intothe Wood.

The surface of the shank c is uneven and covered with elevations anddepressions raised from the body of said shank by rolling or swaging,preferably in the form of spiral ribs 6, the diameter of the shank fromthe highest point of the ribs on one side to a like point on theopposite side being approximately equal to the diameter of the threadedbody at the top or highest point of the thread.

I prefer to form the thread by rolling-in dies;

but the article may be produced by cutting the thread, although some ofthe advantages of my improvement are 5o rolled screw.

attained only in a The form of the spiral ribs 6 in cross-section isshown in Fig. 4t; but said forrn is not essential. Neither is itessential that said ribs shall extend spirally along the shank, althoughthe spiral form is preferred, because spiral ribs cover the completecircle of the shank as viewed in end View, and thereby have a better andfirmer bearing in a round hole.Y AI also prefer that the spiral ribs,although of a steeper pitch, shall extend in the same general directionas the screw-thread- 6o that is, in a right-hand thread I form righthandribs. f f

Fig. 5 represents at d a block of hard wood with a hole 7 bored in it ofa diameter about the same as that of the core 8 of the threaded 65 bodyof the screw. At the right of this hole another hole is shown, intowhich one of my screws has beenascrewed and removed. This hole wasbefore turning in the screw like the y hole 7. 9 designates that portionthereof 7o which received the threaded part of the screw and which ischanged only by the marks of the thread, While l0 represents thatportion of the hole that received the ribbed shank.

In the act of turning in the screw the end of the shank nearest thescrew-thread acts as a reamer and enlarges the diameter of the hole fromthat shown at the portion 9 to the plain cylindrical portion 10.Inasmuch as this portion 10 is made by the ribbed shank in work- 8o ingits way into the wood, it follows that said shank will fill and fit thehole thus formed.

If the hole is not bored before turning in the screwl-as, for instance,when used in soft woodthe gimlet-point and threaded body would form theportion 9 of the hole and the shank would still enlarge the hole whereit enters and change the form of the hole from The screws shown in Figs.1,2, and 3 differ 9o from each other mainly in the extent of the ribsover the shank and in the portion that is covered thereby. In Fig. l theribs extend over the entire length of the shank from the head d to thethreaded body b. In Fig. 2 the 95 ribs extend only over the lowerportion of the shank, leaving a plain portion 1l between the ribs andthe head, the diameter of said plain portion being the same as that ofthe uneven or ribbed portion of the shank. In Fig. 3 the roo ribs are onthe upper portion of the shank, leaving a plain portion l2 larger thanthe core and smaller than the threaded body ot the screw and ribbedportion of the shank, the same representing the original size of theWire. When the screw, Fig. 3,is turned into the Wood, the plain portion12 will by compression slightly enlarge the hole made by the core of thethreaded body and the ribs will ream it out to the size of the ribbedportion'of the shank. This form of screw is particularly adapted forlong screws and saves ribbing the entire length of the shank.

In rolling a thread on a wood-screw the thread is so coarse that thescrew is very liable to be and generally is bent where it runs out atthe shank. By simultaneously rolling the ribs and the thread, especiallyspiral ribs, this bending at the junction of the shank and thread isprevented and a straight screw is produced. In rolling gimlet-pointedWoodscrews there is a severe strain on the stock, having a tendency toforce'the Work endwise away from the portion of the dies that thread thepoint. Y By simultaneously rolling the point, body, and shank the stockis much better held up to the work ot' threading the point.

In rolling a Wood-screw there isa tendency ot the blank to slip, so thatitdoes not rotate in unison with the movement of the threading-dies, andto prevent this slipping it has been found necessary to transverselynotch or rougheu a considerable portion of the surfaces ot thethreading-dies. This is objectionable, because the thread produced issomewhat ragged and rough, instead of being smooth and solid.

By simultaneously rolling the ribbed shank and thread the dies whichroll the ribs act in connection with the blank like a pair of racks anda pinion and insure the proper rotation of the blank, so that the diesmay not be roughened and a smooth and solid thread can be rolled. Whilethe elevations on the shank will in any event bear on the Wall of thehole that is reamed out by said shank, it may be observed that thematerial cut from the wood in roaming ont the hole firmly fills thedepressions in the shank, so as to form practically a solid cylinder.Especially is this the case when the ribs are in the same generaldirection as the thread; but the depressions or grooves will be filledat the end of the shank nearest the thread, even if the ribs extend inthe reverse direction fromthe thread.

A Wood-screw having a head adapted to be engaged by a driver for turningsaid screw axially, a series of elevations and depressions on its shankraised up from the normal diameter of the stock by rolling, a threadedbody of a diameter approximately the same as that of the raised portionof said shank, and a threaded point, substantially as described, and forthe purpose specified.

HORACE K. .T ONES. Vitnesses:

T. S. BISHOP, JAMES SHEPARD.

